Turning simple span into complex span: Time for decay or interference from distractors?

Abstract

We investigated the effects of the duration and type of to-be-articulated distractors during encoding of a verbal list into short-term memory (STM). Distractors and to-be-remembered items alternated during list presentation, as in the complex-span task that underlies much of working-memory research. According to an interference model of STM, known as serial order in a box (SOB; Farrell & Lewandowsky, 2002), additional repeated articulations of the same word between list items should cause minimal further disruption of encoding into STM even though the retention interval for early list items is increased. SOB also predicts that the articulation of several different distractor items should lead to much enhanced disruption if the distractor interval is increased. Those predictions were qualitatively confirmed in 4 experiments that found that it is the type of distractors, not their total duration, that determines the success of encoding a list into STM. The results pose a challenge to temporal models of complex-span performance, such as the time-based resource sharing model (Barrouillet, Bernardin, & Camos, 2004). The results add to a growing body of evidence that memory for the short term is not exclusively governed by purely temporal processes.

Control of information in working memory: Encoding and removal of distractors in the complex-span paradigm

“…As it is highly implausible that participants made an effort to maintain distractors in memory, Experiment 4 adds to the evidence against decay of information in working memory that is no longer relevant, such as distractors or memory items from previous trials (Berman, Jonides, & Lewis, 2009). This conclusion converges with the substantial body of evidence against decay of relevant representations in working memory, at least for verbal materials (Lewandowsky, Duncan, & Brown, 2004;Lewandowsky et al, 2010;Lewandowsky, Oberauer, & Brown, 2009;, 2014.…”

“…It explains the detrimental effect of distractor processing, and why that effect is mitigated by free time following distractors (Oberauer, Lewandowsky, et al, 2012; and the present experiments). It correctly predicts that increasing the number of distractor operations to be carried out in complex span has no effect on memory, unless the distractors differ substantially from each other (Lewandowsky et al, 2010;Lewandowsky, Geiger, & Oberauer, 2008;. SOB-CS correctly predicts the conditions under which similarity between memory items and distractors is helpful .…”

“…Complex-span tasks involve the interleaving of two competing tasks: Encoding elements of a list for immediate serial recall alternates with brief episodes of processing material that is typically unrelated to the memory list. For instance, participants could be asked to remember six consonants in their given order, and presentation of consonants alternates with arithmetic tasks (Turner & Engle, 1989), or with reading aloud a short series of words (Lewandowsky, Geiger, Morrell, & Oberauer, 2010).…”

Rapid Communication: The loss of residual visual memories over the passage of time

“…It also has the added advantage of alleviating concerns about memory maintenance strategies, which is one of the most problematic issues affecting forgetting research (Lewandowsky, Geiger, Morrell, & Oberauer, 2010). Specifically, there is no reason for participants to actively rehearse or refresh stimuli from a previously completed trial -indeed, such a strategy would be counterproductive.…”

Response suppression contributes to recency in serial recall

“…To confirm this, we separately analyzed the number of transposition and intrusion errors at the last output position, again as a function of the number of preceding intrusion errors (with the total number of preterminal errors controlled at two). For Experiment 1, a significant Lewandowsky, Geiger, Morrell, and Oberauer (2010) 3 3 E4 of Lewandowsky, Geiger, and Oberauer (2008) Table 1. increasing linear trend was found for transpositions, F(1, 18) 0 16.64, p 0 .001, but not for intrusions, F(1, 18) 0 1.95, p 0 .18. For Experiment 2, a significant increasing linear trend was likewise found for transpositions, F(1, 10) 0 10.51, p 0 .009, but not for intrusions, F(1, 10) < 1.…”